None.
1. Field of the Invention
The present invention relates to hand tools, and, in particular, relates to pliers, and, in greater particularity, relates to pliers having an adjustable jaw opening to fit different sizes of work pieces.
2. Description of Related Art
The following prior art examples of pliers are incorporated by reference:
One prior art example is long handled, slip-joint pliers having an offset jaw opening with five position settings such as shown by Craftsman model WF 7945381. The handles must be separated by about 90 degrees before any adjustment is allowed which restricts adjustment in close working quarters and the offset jaw opening limits the spaces into which it may be used.
Another prior art example is short handled, slip-joint pliers with a jaw opening symmetrical about a center line through the handles and having only two position settings such as a Craftsman model WF 7945378. The handles must be separated by about 90 degrees before any adjustment is allowed thus restricting changing the settings in close working quarters.
Another prior art example is short handled, slip-joint pliers having a range of continuous jaw openings with a maximum separation angle with laminated construction such as a Stanley model 84-881. The separation angle being solely determined by the size of the work piece upon engagement.
U.S. Pat. No. 6,065,376 discloses automatically adjustable pliers having an offset jaw opening with laminated construction with only a single compound handle.
U.S. Pat. No. 4,893,530 discloses pliers having a control arm between the handles with spring biasing at each end thereof.
U.S. Pat. No. 4,569,132 discloses a cutting tool with compound handles.
U.S. Pat. No. 3,704,620 discloses a compound action tool for crimping purposes with a pair of jaws.
U.S. Pat. No. 832,804 discloses a cutting tool having compound handles wherein the jaw opening is not adjustable for different sized work pieces.
Thus, there exists a need for a manually adjustable slip-joint pliers having selective separation angles between the jaw members for gripping work pieces of different sizes and further allowing adjustment with minimal movement of the handles of the pliers.
Slip-joint pliers of the present invention comprise, in one embodiment, a pair of compound handles pivotally attached to jaw means being upper and lower jaw members having a manually adjustable slip-joint therein for providing at least two different maximum jaw opening positions, each having a different separation angle. The jaw openings are selectable by movement of a lever, for example, attached to a keyed pivot pin in the slip-joint. Further, the jaw openings are selectable with minimal movement of the compound handles as a result of spring biasing between the jaw members. A further embodiment without the compound handles has the spring biasing between the jaw arms and a sliding bracket mounted on pivot pins in the handles attached to the jaw arms to restrict the separation of the handles in an outwardly direction so that the spring will constantly bias the jaw arms apart such that the operation of the lever described herein, or other device, allows the jaw members to be adjusted.
The method of using the pliers of the present invention requires that the manually adjustable slip-joint be positioned in a disengaged mode to allow the jaw members to be moved to a predetermined separation angle. At which point, the slip-joint is engaged which allows the use of the pliers to grip work pieces of different sizes. By use of either one or both hands, the jaw members may be moved to another predetermined separation angle.
Therefore, one object of the present invention is to provide improved pliers with a slip-joint that is spring biased so that jaw members may have several different separation angles for gripping work pieces of different sizes.
Another object of the present invention is to provide compound pliers with the manually adjustable slip-joint having several jaw openings to accommodate different sized work pieces.
Another object of the present invention is to provide compound pliers having several jaw openings which may be selected quickly and easily with either one or both hands by the use of the manually adjustable slip-joint.
Another object of the present invention is to provide compound pliers having several jaw openings which may be selected with minimal movement of the compound handles to allow adjustment.
Another object of the present invention is to provide improved pliers having several jaw openings which may be selected with minimal movement of the handles to allow adjustment.
Another object of the present invention is to provide compound pliers having several jaw openings which may be selected in close quarters.
Another object of the present invention is to provide compound pliers having several jaw openings which may grip the work piece straight on as compared to offset jaws.
These and many other objects and advantages of the present invention will be ready apparent to one skilled in the pertinent art from the following detailed description of a preferred embodiment of the invention and the related drawings.